根据view创建bitmap

public static Bitmap createBitmapFromView(View view) {
        if (view instanceof ImageView) {
            Drawable drawable = ((ImageView) view).getDrawable();
            if (drawable != null && drawable instanceof BitmapDrawable) {
                return ((BitmapDrawable) drawable).getBitmap();
            }
        }
        view.clearFocus();
        Bitmap bitmap = createBitmapSafely(view.getWidth(),
                view.getHeight(), Bitmap.Config.ARGB_8888, 1);
        if (bitmap != null) {
            synchronized (sCanvas) {
                Canvas canvas = sCanvas;
                canvas.setBitmap(bitmap);
                view.draw(canvas);
                canvas.setBitmap(null);
            }
        }
        return bitmap;
    }
    
public static Bitmap createBitmapSafely(int width, int height, Bitmap.Config config, int retryCount) {
        try {
            return Bitmap.createBitmap(width, height, config);
        } catch (OutOfMemoryError e) {
            e.printStackTrace();
            if (retryCount > 0) {
                System.gc();
                return createBitmapSafely(width, height, config, retryCount - 1);
            }
            return null;
        }
    }